The present invention relates to navigation systems, and more particularly, the present invention relates to a feature provided by a navigation system whereby a user of the system is provided with backup driving instructions.
There are various computer architectures for navigation systems that provide navigation-related features (including map-related features). In one type of architecture for a navigation system, end users (such as vehicle drivers, passengers, and others) use a wireless communications system to obtain navigation-related services or data from a remotely located navigation services provider. The end users use various computer platforms (e.g., different kinds of electronic devices and/or systems) to connect to the wireless communications system in order to access the remotely located navigation service provider. Associated with the remotely located navigation services provider is a geographic database. When an end user uses his/her computer platform to request a navigation-related service or data, the remotely located navigation service provider accesses the geographic database associated therewith and then provides the requested service or data to the requesting end user""s computer platform via the wireless communications system.
This type of navigation system architecture provides several advantages. One advantage relates to providing updated data. There is a continuing need to update the data used by a navigation system. For example, new streets are built, road construction closes roads, detours are established, new businesses open, posted speed limits change, new turn restrictions are established at intersections, streets are renamed, and so on. These kinds of changes can affect travel through a geographic region. Accordingly, the data used by a navigation system should be updated on a regular basis to accurately reflect changes in the represented geographic features. A computer architecture in which end user computing platforms obtain data wirelessly from a single central geographic database associated with a navigation services provider affords an advantage with respect to the updating of the geographic data. With such a computer architecture, updates need to be applied only to the central database.
Although there are advantages associated with a navigation system architecture in which individual end user computer platforms request and obtain navigation-related services and data wirelessly from a single central geographic database associated with a navigation services provider, there are considerations to be addressed. One consideration relates to the need for continuous availability of navigation-related services and data wirelessly. According to one type of navigation system architecture, a navigation services provider provides navigation-related services and data to an end user while the end user is traveling within a coverage area. A wireless communications system, associated with the navigation services provider, is available continuously (or relatively continuously) throughout the coverage area. End users located throughout the coverage area use their computing devices to access the wireless communications system in order to obtain navigation-related services and data from the navigation services provider.
According to this type of system, each end user maintains one or more relatively continuous sessions with the navigation services provider. During each session, the end user and the navigation services provider may exchange several data messages. As an example, the end user may communicate a message to the navigation services provider requesting driving instructions for traveling to a destination. In response, the navigation services provider sends a message that includes instructions for starting on the route to the destination. As the end user follows the route, the end user sends additional messages to the navigation services provider. Each additional message from the end user to the navigation services provider may include an update of the end user""s position as he/she proceeds along the route. As messages from the end user are received by the navigation services provider, the navigation services provider prepares and sends new messages containing additional instructions for continuing along the route. In this manner, the navigation services provider can provide the end user with instructions that are timely and relevant with respect to the end user""s progress along the route.
With this type of system, it is not necessary that the end user and navigation services provider maintain a continuous communications link. However, if communications between the end user and the navigation services provider are interrupted for a relatively long a period of time, the end user may not have downloaded sufficient information from the navigation services provider for continuing further along the calculated route toward the destination. Interruptions in communications between end users and the navigation services provider may occur for various reasons, such as equipment failure, heavy usage, and so on. The interruption of navigation-related services may be inconvenient for some end users. Accordingly, it would be preferable to reduce or minimize any inconvenience to end users of this navigation system architecture occasioned by the lack of navigation-related services.
To address these and other objectives, the present invention comprises a navigation method and system whereby users of the systems are provided with backup driving instructions. A wireless communications system allows end users"" computing devices to receive dynamic route guidance from a remotely located navigation services provider. The dynamic route guidance provides each end user with maneuvering instructions at appropriate locations along a route to a desired destination. In addition to the dynamic route guidance, the navigation service provider also provides each end user with backup driving instruction data. The backup driving instruction data are used to provide each end user with backup driving instructions for traveling to the end user""s desired destination. The backup driving instruction data are used in case wireless communications between the end user and the navigation services provider are interrupted.